PubMed Health⌕ Search

Biomedical subjects

C Ruiz

Publications and source records attributed to C Ruiz.

At least 37 records · Page 2Linked to original sources
PubMed2001

Step-by-step uncoordination of the pyrazolyl rings of hydrotris(pyrazolyl)borate ligands in comlexes of Rh and RhIII.

Compounds of rhodium(I) and rhodium(III) that contain ancillary hydrotris(pyrazolyl)borate ligands (Tp') react with monodentate and bidentate tertiary phosphanes in a step-wise manner, with incorporation of P-donor atoms and concomitant replacement of the Tp' pyrazolyl rings. Accordingly, [Rh(kappa3-TpMe2)(C2H4)(PMe3)] (1b), converts initially into [Rh(kappa2-TpMe2)-(PMe3)2] (3), and then into [Rh(kappa1-TpMe2)-(PMe3)3] (2) upon interaction with PMe3 at room temperature, in a process which can be readily reversed under appropriate experimental conditions. Full disengagement of the Tp' ligand is feasible to give Tp' salts of rhodium(I) complex cations, for example, [Rh(CO)(dppp)2]-[TpMe2,4-Cl] (5; dppp = Ph2P(CH2)3PPh2), or [Rh(dppp)2][TpMe2,4-Cl] (6). Bis(hydride) derivatives of rhodium(III) exhibit similar substitution chemistry, for instance, the neutral complex [Rh(Tp)-(H)2(PMe3)] reacts at 20 degrees C with an excess of PMe3 to give [Rh(H)2-(PMe3)4][Tp] (9b). Single-crystal X-ray studies of 9b, conducted at 143 K, demonstrate the absence of bonding interactions between the [Rh(H)2(PMe3)4]+ and Tp ions, the closest Rh...N contact being at 4.627 A.

Journal Article↗
PubMed2001

The diversification of Citrus clementina Hort. ex Tan., a vegetatively propagated crop species.

Clementines, due to their high quality, are one of the most important cultivated citrus mandarins. As in the case of sweet orange and satsuma mandarins, genetic variability within this species is minimal when analyzed by molecular markers, because the existing varieties have not been obtained through hybridization, but through the selection of spontaneous mutations affecting traits of agronomic interest. This would explain, at least in part, the greater diversity for agronomic traits when compared to the variability for molecular markers. Another possible (nonexclusive) reason is that the types of molecular marker used are not focused on the kind of molecular change mainly involved in the origination of new clementine cultivars; i.e., are all sources of variation equally involved in the diversification of these plants? To answer this question, different kinds of markers based on primers of random sequence, simple sequence repeats, and retrotransposon sequences that may reveal point mutations, and somatic recombination and transposon activity, respectively, were used to compare the level of variability among 24 clementine varieties. Their ISSR, RAPD, and AFLP analysis provided only two polymorphic bands, distinguishing just two varieties. No variability was found by SSRs, i.e., no new allele arising through somatic recombination was detected. Instead, the amplification of sequences adjacent to retrotransposons yielded a higher number of polymorphisms (14.6 vs 2.4% for the previous mentioned marker types). Two geographical distant groups, one from North Africa and the other from Spain, have evolved in agreement with polymorphisms based on IRAP markers anchored to, at least, two different Copia-like retrotransposon sequences. Therefore, this study suggests that the DNA of this type of mobile elements is evolving faster than the DNA of other markers in this clonal lineage.

Alleles↗
PubMed2001

[Morphological changes in adenotonsillar tissue as early manifestation of asymptomatic HIV patient].

The HIV virus induces in the host several changes in your immunological system, which heads to the AIDS. We report two cases diagnosed by pathological studies after adenotonsilectomy for adenotonsilar hypertrophy. The diagnosis of HIV patients is suspected by epidemiologic (risk groups) or clinical features (opportunist diseases). But, it exists a early diagnosis, the histological findings in the extranodal lymphoid tissues, unusual on the literature. These phenomenons re-enforce the contamination way by means of the superior aerodigestive tract mucosis.

Adenoidectomy↗
PubMed2001

Laryngeal preservation with supracricoid partial laryngectomy results in improved quality of life when compared with total laryngectomy.

OBJECTIVES/HYPOTHESES: Study 1: To assess the oncologic outcome following supracricoid partial laryngectomy (SCPL). Study 2: To compare the quality of life (QOL) following SCPL to total laryngectomy (TL) with tracheoesophageal puncture (TEP). Study 3: To analyze whole organ TL sections to determine the percentage of lesions amenable to SCPL STUDY DESIGN: Study 1: A retrospective review of patients who underwent SCPL. Study 2: A non-randomized, prospective study using QOL instruments to compare patients who underwent either SCPL or TL Study 3: A retrospective histopathologic study of TL specimens assessed for the possibility of performing an SCPL. METHODS: Study 1: Twenty-five patients with carcinoma of the larynx underwent SCPL between June 1992 and June 1999. Various rates of oncologic outcome were calculated. Study 2: Thirty-one patients participated in the QOL assessment. This included the SF-36 general health status measure, the University of Michigan Head and Neck Quality of Life (HNQOL) instrument, and the University of Michigan Voice-Related Quality of Life (VRQOL) instrument. Study 3: Ninety surgical specimens were obtained and studied from the total laryngectomy cases in the Tucker Collection. Multiple sites were evaluated for the presence of carcinoma A computer program was written to classify whether the patient was amenable to SCPL. RESULTS: Study 1: The overall local control rate was 96% (24/25). The local control rate following SCPL with cricohyoidoepiglottopexy (CHEP) was 95% (20/21). The local control rate following SCPL with cricohyoidopexy (CHP) was 100% (4/4). Study 2: The SCPL had significantly higher domain scores than TL and TEP in the following categories for the SF-36: physical function, physical limitations, general health, vitality, social functioning, emotional limitations, and physical health summary. The significantly higher domains for the SCPL when compared with the TL and TEP for the HNQOL were eating and pain. Finally, when voice-related QOL was assessed with the V-RQOL, the domains of physical functioning and the total score were significantly better with SCPL when compared with TL and TEP. Study 3: Forty of 90 (44%) laryngeal whole organ specimens were determined to be resectable by SCPL. In 16 (18%) specimens, the patients could have undergone SCPL with CHEP and in 24 (27%) specimens the patients could have undergone SCPL with CHP. Among the 40 (44%) specimens determined to be able to have undergone SCPL, 19 were glottic (1 T1, 15 T2, 3 T3) and 21 were supraglottic (9 T2, 12 T3). CONCLUSIONS: 1) A review of the literature and an analysis of the data in this study indicate that excellent local control may be expected following SCPL. 2) The QOL following SCPL, as measured by three validated QOL instruments, is superior to TL with TEP. 3) A histologic assessment of whole organ sections of TL specimens indicates that many patients who have been subjected to TL may have been candidates for SCPL. 4) If the indications and contraindications are rigorously adhered to, SCPLs are reasonable alternatives to TL in selected cases.

Adult↗
PubMed2001

The anaerobic SBR process: basic principles for design and automation.

This study has determined the purification performance and the basic principles for the design of an anaerobic SBR (ASBR) to be used to treat wastewater generated in the food industries. Two ASBR's were set up and one fed with a slaughterhouse effluent at low concentration, the other with concentrated dairy wastewater. The maximum loading rate applied should not exceed 4.5 g of COD/L/day for the dilute effluent and 6 g of COD/L/day for the concentrated effluent. At higher loading rates, the reactors become difficult to operate, mainly because of sludge removal problems, and purification efficiency declines. A detailed study of the kinetics (TOC, VFA, rate of biogas production) throughout one treatment cycle led to the development of a simple control strategy based on the monitoring of the biogas production rate which was then applied to the reactor treating the dairy wastewater. After automation, the reactor worked free of problems at an average pollution load of 5.4 g of COD/L/day.

Abattoirs↗
PubMed2000

Krüppel-homolog, a stage-specific modulator of the prepupal ecdysone response, is essential for Drosophila metamorphosis.

We have characterised a P-element-induced prepupal mutant of Drosophila melanogaster which after an apparently normal embryonic and larval development fails to complete head eversion, an essential step in metamorphosis. The P-element insertion disrupts an ecdysone-regulated transcript which, although expressed during embryonic and larval stages, appears critical for preparing the late prepupal response to ecdysone. By a combination of molecular and genetic studies, in which we recovered new alleles, we show that the locus is complex, containing at least two distinct promoters. Its transcripts contain a short region described previously by R. Schüh et al. (1986, Cell 47, 1025-1032), who screened for homologues of the Krüppel gene. Our studies on the corresponding gene, named Krüppel-homolog (Kr-h), add to a growing body of evidence that specific isoforms of a number of key genes are implicated in both embryogenesis and metamorphosis.

Amino Acid Sequence↗
PubMed2000

[Factors related to drug consumption in children's population].

BACKGROUND: To analyse the correlates of drug consumption in children's population. METHOD: Analyse interviews corresponding to children younger than 15 years old of the Catalan Health Survey (n = 2,433). RESULTS: The 25% consumed some drug in the previous 2 days. The factors related to drug consumption were low age, living in Barcelona (OR = 1.3), reporting double coverage (OR = 1.6), physician visits in the past 15 days (OR = 2.4), and reporting health problems. CONCLUSIONS: Drug consumption in children is high. It seems necessary to improve the education of families and health professionals related to drug consumption.

Adolescent↗
PubMed2000

Substitution and hydrogenation reactions on rhodium(I)-ethylene complexes of the hydrotris(pyrazolyl)borate ligands T (T = Tp, TpMe2).

The bis(ethylene) Rh species TpMe2Rh(C2H4)2(1*) (TpMe2 = tris(3,5-dimethyl-1-pyrazol-1-yl)hydroborate) has been obtained from [RhCl(C2H4)2]2 and KTpMe2. Complex 1* easily decomposes in solution to give mainly the butadiene species TpMe2Rh(eta74-C4H6). In the solid state its thermal decomposition follows a different course and the allyl TpMe2RhH(syn-C3H4Me) is cleanly obtained as a mixture of exo and endo isomers. The complexes Tp'Rh(C2H4)2 (Tp' = Tp, TpMe2) afford the monosubstituted species Tp'Rh(C2H4)(PR3) upon reaction with PR3 but react differently with L = CO or CNR: the Tp compound gives dinuclear [TpRh]2(mu-L)3 complexes, while, in the case of 1*, TpMe2Rh(C2H4)(L) species are obtained. The ethylene ligand of complexes TpMe2Rh(C2H4)(PR3) is labile, and several peroxo compounds of composition TpMe2Rh(O2)(PR3) have been isolated by their reaction with O2. All the mononuclear Rh(I) complexes are formulated as 18e- trigonal bipyramidal species on the basis of IR and NMR spectroscopic studies. A series of dihydride complexes of Rh(III) of formulation Tp'RhH2(PR3) have been prepared by the hydrogenation of the corresponding ethylene derivatives. Complexes [TpRh]2(mu-CNCy)3, TpMe2Rh(C2H4)(PEt3), and TpMe2Rh(O2)(PEt3) have been further characterized by X-ray diffraction studies.

Journal Article↗
PubMed2000

Regulatory mechanisms for modulation of signaling through the cell integrity Slt2-mediated pathway in Saccharomyces cerevisiae.

Signal transduction mediated by the mitogen-activated protein kinase (MAPK) Slt2 pathway is essential to maintain the cell wall integrity in Saccharomyces cerevisiae. Stimulation of MAPK pathways results in activation by phosphorylation of conserved threonine and tyrosine residues of MAPKs. We have used an antibody that specifically recognizes dually phosphorylated Slt2 to gain insight into the activation and modulation of signaling through the cell integrity pathway. We show that caffeine and vanadate activate this pathway in the absence of osmotic stabilization. The lack of the putative cell surface sensor Mid2 prevents vanadate- but not caffeine-induced Slt2 phosphorylation. Disruption of the Rho1-GTPase-activating protein genes SAC7 and BEM2 leads to constitutive Slt2 activation, indicating their involvement as negative regulators of the pathway. MAPK kinases also seem to participate in signaling regulation, Mkk1 playing a greater role than Mkk2 in signal transmission to Slt2. Additionally, one of the phosphatases involved in Slt2 dephosphorylation is likely to be the dual specificity phosphatase Msg5, since overexpression of MSG5 in a sac7Delta mutant eliminates the high Slt2 phosphorylation, and disruption of MSG5 in wild type cells results in increased phospho-Slt2 levels. These data present the first evidence for a negative regulation of the cell integrity pathway.

DNA-Binding Proteins↗
PubMed2000

Double bond content of phospholipids and lipid peroxidation negatively correlate with maximum longevity in the heart of mammals.

Free radical damage is currently considered a main determinant of the rate of aging. Unsaturated fatty acids are the tissue macromolecules most sensitive to oxidative damage. Therefore, the presence of relatively low degrees of fatty acid unsaturation is expected in the tissues of longevous animals. In agreement with this prediction, fatty acid analyses of heart phospholipids in eight mammals ranging in maximum life span (MLSP) from 3.5 to 46 years showed that their total number of double bonds is negatively correlated with MLSP (r = -0.78, P < 0.02). The low double content of longevous mammals was not due to a low polyunsaturated fatty acid content. Instead, it was mainly due to a redistribution between types of polyunsaturated fatty acids from the highly unsaturated docosahexaenoic acid (22:6n-3) to the less unsaturated linoleic acid (18:2n-6) in longevous animals (r = -0.89, P < 0.003 for 22:6n-3 and r = 0.91, P < 0.002 for 18:2n-6 versus MLSP), where n = number of different animals in each species. This redistribution suggests that one of the mechanisms responsible for the low number of fatty acid double bonds is the presence of low desaturase activities in longevous animals, although other causing factors must be involved. In agreement with the low degree of fatty acid unsaturation of longevous mammals, the sensitivity to lipid peroxidation (r = -0.87; P < 0.005) and the in vivo lipid peroxidation (r = -0.86, P < 0.005) in the heart were also negatively correlated with MLSP across species. These results, together with previous ones obtained in rodents, birds, and humans, suggest that the low degree of tissue fatty acid unsaturation of longevous homeothermic animals could have been selected during evolution to protect the tissues against oxidative damage.

Aging↗
PubMed2000

Interventional treatment of lateral tunnel dehiscence in a total cavopulmonary connection using a balloon expandable covered stent.

In this paper we present a patient with dehiscence of an intra-atrial tunnel previously constructed during a total cavopulmonary connection procedure. We describe the use of a custom made covered stent to seal off the dehisced segment, and abolish the intra-cardiac shunting. We believe this is the first account of such a procedure being undertaken.

Abnormalities, Multiple↗
PubMed2000

Paradoxical vocal fold motion: presentation and treatment options.

Paradoxical vocal fold motion is a rare disorder in which adduction of the folds occurs on inspiration. The disorder presents with signs of airway obstruction and often airway distress, so proper diagnosis by the otorhinolaryngologist is critical to subsequent management. We present a retrospective review of 10 patients with the diagnosis of paradoxical vocal fold motion seen over a 6-year period. Eight patients were females, and 6 required an acute airway intervention at presentation; 3 patients eventually underwent tracheotomy for respiratory decompensation. Six patients had a prior diagnosis of asthma, and this was determined to contribute to their respiratory status. Five patients were treated with botulinum toxin and 2 with flexible nasolaryngoscopic biofeedback, which improved the outcome. A review of the literature confirms a female predominance of patients presenting with paradoxical adduction and airway distress, often with a history of asthma and psychopathology. Our experience with botulinum toxin and biofeedback suggests that these procedures are viable treatment options in the management of patients with this disorder.

Adolescent↗
PubMed2000

Expression of molecules involved in antigen presentation and T cell activation (HLA-DR, CD80, CD86, CD44 and CD54) by cultured human osteoblasts.

BACKGROUND: Osteoblasts express the CD44 antigen and HLA class II antigens, molecules which, together with other costimulatory molecules such as CD80, CD86, and CD54, are involved in antigen presentation and T cell activation. The aim of this study was to investigate the expression of these molecules in human osteoblasts. METHODS: Human osteoblastic cells obtained from samples of normal bone obtained during mandibular osteotomy were isolated, maintained in culture, and characterized. The identity of the cells was confirmed by their alkaline phosphatase activity and their capacity to produce osteocalcin. Flow cytometry was used to examine the expression HLA-DR, CD80, CD86, CD44, and CD54 molecules involved in immune activities. RESULTS: We detected the expression of CD10, CD44, and HLA-DR antigens, molecules involved in antigen presentation in cultured osteoblastic cells. Although the cells were negative for CD45, the leukocyte common antigen and CD14 (an antigen detected on macrophages), they expressed CD54, CD80, and CD86 antigens, which are also involved in the mechanisms of antigen presentation to and activation of T cells. CONCLUSIONS: Our results suggest that osteoblastic cells or a subpopulation of these cells may have immune functions in bone. Further studies in which immune functions are assessed will be needed to test this hypothesis.

Adult↗
PubMed2000

Effect of exopolysaccharide V2-7, isolated from Halomonas eurihalina, on the proliferation in vitro of human peripheral blood lymphocytes.

The immunomodulatory activity of the exopolysaccharide V2-7, a sulfated polymer excreted by the moderately halophilic bacteria Halomonas eurihalina, was studied in vitro. [3H]thymidine incorporation and flow-cytometry measurements showed that this exopolysaccharide enhanced the unspecific proliferation of human lymphocytes in response to the presence of anti-CD3 monoclonal antibody. It was effective at concentrations of less than 1 microg/ml, maximum activity being achieved at 0.2 microg/ml.

Adjuvants, Immunologic↗
PubMed1999

GEM, a cluster of repetitive sequences in the Drosophila subobscura genome.

GEM is a new family of repetitive sequences detected in the D. subobscura genome. Two of the four described GEM elements encompass a heterogeneous central module, with no detectable ORF, flanked by two long inverted repeats. These elements are composed of a set of repetitive modules, which are inverted repeat (IR), direct repeat (DR), palindromic sequence (PS), long sequence (LS) and short sequence (SS). These five modules can be found either clustered or dispersed as single modules in the D. subobscura genome, in euchromatic and heterochromatic regions. In addition to the 3' region of Adh retrosequences, single IR and LS blocks were found associated with the promoter region of different genes, in particular, LS-like blocks have also been found associated with functional genes in D. melanogaster and D. virilis. Conversely, the DR block is highly similar to satellite DNAs from some other species of the obscura group. In addition, GEM elements share some structural features with IS elements described in different Drosophila species. It is likely that both GEM and IS sequences would be vestiges of an ancestral transposable element.

Alcohol Dehydrogenase↗